The invention aims to provide a novel biogas digester. The biogas digester comprises a digester body, a feed channel, a discharge channel, residue removers, a stirring system and two bins, wherein the feed channel is arranged at one end of the digester body and the discharge channel is arranged at the other end of the digester body; a skylight opening with a cover and a gas guide tube are formed in the top of the digester body; at least one channel is formed in the bottom of the digester body; a plurality of residue removers are connected on the channels in a sliding manner; the stirring system is installed in the biogas digester and is used for stirring raw materials. The biogas digester can utilize human and animal excreta and various biomass raw materials as fermentation raw materials and also has high biogas yield and strong residue removal and control capacities.